1. Field of the Invention
This invention relates to the field of disk drive suspensions. More particularly, this invention relates to the field of a low profile suspension having a cavity formed therein for receiving a microactuator.
2. Description of Related Art
The suspension is the component of a magnetic hard disk drive, or other type of disk drive such as an optical disk drive, that holds the read/write head over the surface of the spinning disk. A servo-controlled voice coil motor (VCM) moves the suspension and thus positions the read/write head precisely over the desired data track on the disk.
Due to the increasing data densities in modern disk drives, in addition to the VCM for coarse positioning of the read/write head, many suspensions now also incorporate a microactuator on the suspension itself for extremely fine and fast positioning of the read/write head. Suspensions that incorporate a microactuator are sometimes referred to as dual-stage actuator (DSA) suspensions. Piezoelectric devices, typically lead zirconate titanate (PZT) devices, are commonly used as the microactuator motors in DSA suspensions.
U.S. Pat. No. 6,614,627 issued to Shimizu et al. discloses a DSA suspension having two PZT motors for micropositioning of the read/write head, and folded springs protruding from either side of the suspension, commonly called “C-springs,” for flexibility.
U.S. Pat. No. 6,856,075 issued to Houk et al. discloses an adhesive control feature consisting of a relief defining a channel under or partially under or adjacent to a PZT transducer to channel and control the flow of adhesive and prevent the adhesive from flowing or wicking underneath the PZT toward the center of the PZT which would reduce its effective stroke length.
U.S. Pat. No. 6,219,203 issued to Arya et al. discloses a suspension which purports to eliminate the separate forming step of bending the lateral edges of the load beam to create edge rails for stiffness, by partially etching the load beam on both sides to create truss-like rib structures in the load beam, the rib structures providing mechanical stiffness.
U.S. Pat. No. 7,375,930 issued to Yang et al. discloses a suspension having a microactuation device integrated on the gimbal.
U.S. Pat. No. 7,459,835 issued to Mei et al. discloses a suspension having a cantilevered bending motor disposed on the load beam.
One of the design goals of a disk drive suspension is a low profile. A low profile suspension allows the individual disks within a multiple disk hard drive, each disk having its own suspension to read and write data to it, to be stacked closely together thus decreasing the height of the multiple disk assembly.
Another design goal is a high resonant frequency of the suspension in both the vertical dimension and the horizontal (sway) dimension. Similarly, it is desired that the suspension exhibit a low gain at the frequencies at which the suspension will be excited due to vibration of the disk, movement of the suspensions by the VCM, and micro movement of the suspension by the PZT.